Refactor render graph & DSL; remove material system

- Major optimization of Ghost.RenderGraph.Concept: pooled resources, zero-allocation hot paths, explicit queue types, and batch barrier APIs.
- Migrated Ghost.DSL shader compiler to ANTLR4-based parser; removed hand-written parser, added grammar files and semantic model conversion.
- Added CollectionPool/ListPool for pooled list management.
- Updated documentation for new architecture and performance.
- Removed Ghost.Shader.Concept (material/material system) from repo and solution.
- README.md replaced with a brief project statement.

Ghost.Graphics/test.gsdef

@@ -21,20 +21,6 @@ shader "MyShader/Standard"
             color_mask = all;
         }
 
-        keywords
-        {
-            local TEST_KEYWORD, TEST_KEYWORD2;
-            local TEST_KEYWORD3;
-        }
-
-        hlsl
-        {
-            float Test()
-            {
-                return 1.0;
-            }
-        }
-
         mesh "F:/csharp/GhostEngine/Ghost.Graphics/RenderPasses/ShaderCode.hlsl" : "MSMain";
         pixel "F:/csharp/GhostEngine/Ghost.Graphics/RenderPasses/ShaderCode.hlsl" : "PSMain";
     }